Abstract

This chapter provides a practical theoretical foundation and perspective on the performance of various thin-film lateral pn-junction solar devices under illumination. It focuses on Si- and Ge-based homo-junctions, as well as ZnO/Si (TypeI) and GaN/Si (Type-II) based hetero-junctions. Theoretical models assume polycrystalline or amorphous semiconductor materials. The study demonstrates that highlydoped Si- and Ge-based homo-junction architectures show great promise for highperformance solar devices. By utilizing published experimental results, the predicted performances of homo-junction and hetero-junction solar devices are primarily compared at room temperature. Additionally, the chapter addresses the behaviors of these devices at low and high temperatures, considering various applications. The results reveal the superiority of Si- and Ge-based homo-junctions. The chapter delves into the theoretical aspects, providing a robust understanding of the principles governing the performance of these solar devices. It evaluates the advantages and challenges associated with each type of junction, offering a comprehensive analysis of their operational efficiencies. Through detailed comparisons and analysis, the study underscores the potential of Si- and Ge-based homo-junctions in advancing solar technology. This investigation into the practical and theoretical aspects of thin-film lateral pn-junction solar devices serves as a valuable resource for understanding their performance under different conditions. It highlights the critical role of material selection and doping strategies in optimizing device efficiency, paving the way for future research and development of high-performance solar technologies.